Sanitary napkin with rapid drainage and anti-reverse osmosis functions and preparation method of sanitary napkin

Abstract

The invention relates to the technical field of disposable hygienic products, in particular to a sanitary napkin with quick drainage and anti-reverse osmosis functions and a preparation method of the sanitary napkin with the quick drainage and anti-reverse osmosis functions, the sanitary napkin comprises a sanitary napkin body, and a functional core body is arranged in the middle of the sanitary napkin body; the functional core body sequentially comprises a surface layer, a flow guide layer, a sandwich structure layer, a water-absorbent resin layer and a dust-free paper layer from top to bottom, and the functional core body is coated by a pure cotton surface layer and a PET (Polyethylene Terephthalate) bottom film. The sanitary napkin can rapidly absorb liquid without reverse osmosis, and meanwhile has good air permeability, softness and deodorization capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of disposable sanitary products, and particularly relates to a sanitary napkin with a function of rapid liquid conduction and anti-backflow and a preparation method thereof. Background Art

[0002] With the development of the economy and the improvement of women's health awareness, the market demand for women's sanitary products has been increasing continuously. As an essential sanitary care product for women during menstruation, the safety, comfort, and functionality of sanitary napkins have always been the focus of attention of researchers. The market development of sanitary napkins has gone through several stages. In the early days, women mainly used simple absorbent materials such as self-made menstrual cloths to cope with menstruation. In 1920, the world's first sanitary napkin brand, "Kotex", emerged, and sanitary napkins began to be mass-produced and gradually replaced the reusable menstrual belts. In 1956, the first adhesive-fixed sanitary pad was invented. In 1972, the first strap-free sanitary napkin appeared. In 1980, sanitary napkins with side wings appeared abroad to prevent side leakage. At the same time, Chinese women really started using sanitary napkins half a century later than in Europe and America. As of 2020, the sanitary napkin industry in China has a development history of nearly 40 years, and the number of manufacturers has increased rapidly from dozens in 1990 to more than 1,000. The domestic brand Hengan occupies the main market.

[0003] Currently, the structure of sanitary napkins usually includes a surface layer, a middle layer, an absorption layer, and a bottom film layer. Some products will also add a diversion layer between the surface layer and the absorption core layer to enhance the absorption performance. However, there are still some problems with the existing surface layer materials of sanitary napkins. For example, when fluff pulp is used as the main absorbent and liquid-locking material, due to the relatively high filling amount required, the product has problems such as a relatively high overall thickness, stuffiness, and fluff pulp swelling and displacement and backflow after liquid absorption. At the same time, when using a composite core body of high molecular SAP resin combined with fluff pulp and its paper-like products, although the product thickness can be controlled to a certain extent, due to the material characteristics, there are often problems such as no elastic buffer when pressed, low liquid conduction and absorption rate, and backflow.

[0004] In order to improve the performance of sanitary napkin products, researchers have proposed a large number of improvements to the structure of sanitary napkins. For example, CN113069278B discloses an "anti-side leakage sanitary napkin". The inner side of this sanitary napkin is equipped with a tubular container inserted into the vagina, which can reduce the amount of menstrual blood flowing into the sanitary napkin body and keep the vulva dry and comfortable. However, when using this sanitary napkin, the insertion of the tubular container into the vagina may cause problems such as distending pain and discomfort for the user during activities.

[0005] For another example, CN106361501B discloses "a sanitary napkin". An embedding groove is provided in the middle of the sanitary napkin, and a highly absorbent layer is provided in the embedding groove. The highly absorbent layer is a superabsorbent resin. When the sanitary napkin body and the highly absorbent layer are used, an absorption force difference will be formed, so that the liquid is firmly adsorbed in the highly absorbent layer. However, although the superabsorbent resin has a large adsorption capacity, the adsorption rate per unit time is small, and there may still be a problem of reverse osmosis. At the same time, this patent does not mention or solve the problem of comfort.

[0006] Therefore, it is urgent to develop a sanitary napkin that can quickly absorb liquid without reverse osmosis, and at the same time has good air permeability, softness and deodorization ability. Summary of the Invention

[0007] The main object of the present invention is to provide a sanitary napkin with a function of rapid liquid conduction and anti-reverse osmosis and a preparation method thereof. The sanitary napkin can quickly absorb liquid without reverse osmosis, and at the same time has good air permeability, softness and deodorization ability.

[0008] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0009] On the one hand, the present invention provides a sanitary napkin with a function of rapid liquid conduction and anti-reverse osmosis, including a sanitary napkin body. A functional core is provided in the middle of the sanitary napkin body. The functional core sequentially includes a surface layer, a diversion layer, a sandwich structure layer, a water-absorbing resin layer and a non-woven fabric layer from top to bottom. The functional core is coated with a pure cotton surface layer and a PET bottom film.

[0010] The present application does not make special limitations on the material of the surface layer, which is a commonly used material in the art, including but not limited to the material of the surface layer being non-woven fabric.

[0011] The present application does not make special limitations on the material of the diversion layer, which is a commonly used material in the art, including but not limited to the material of the diversion layer being cotton fiber.

[0012] In some embodiments, the sandwich structure layer is composed of an upper cloth surface, a support layer and a lower cloth surface.

[0013] The present application does not make special limitations on the material of the upper cloth surface. The material of the upper cloth surface is a commonly used unidirectional moisture-permeable material in the art, including but not limited to the material of the upper cloth surface being polypropylene.

[0014] The present application does not make special limitations on the material of the lower cloth surface. The material of the lower cloth surface is a commonly used water-absorbing material in the art, including but not limited to the material of the lower cloth surface being polyester.

[0015] In some embodiments, the support layer is composed of monofilaments or multifilaments arranged vertically or crosswise.

[0016] In some embodiments, the monofilament and the multifilament are respectively spun from a single and multiple hydrophobic fibers.

[0017] The functional core of the sanitary napkin of the present application is composed of each layer that is compatible and synergistic with each other, improving the soft and comfortable performance, air permeability, rapid moisture conduction performance, and anti-seepage performance of the sanitary napkin, enabling the surface layer of the sanitary napkin to remain dry. The reasons may be as follows. On the one hand, the upper cloth surface of the sandwich structure layer of the present application selects a material with unidirectional moisture conduction performance to prevent the back-seepage of the permeate liquid, thus keeping the surface layer dry. The support layer is composed of monofilaments or multifilaments obtained by spinning hydrophobic fibers through an orderly arrangement, having a certain hollow structure. This structure can improve the air permeability of the sanitary napkin, reduce the sense of stuffiness, and at the same time has good pressure-touch rebound performance, which can improve the soft and comfortable performance of the sanitary napkin. The lower layer selects a material with good water absorption performance. When the sandwich structure layer composed of the three is used, when the liquid penetrates into the upper layer, the support layer will quickly divert the liquid downward due to hydrophobic action and gravity. In addition, the upper layer will not spread the liquid due to hydrophobic action, thus forming a huge pressure difference to accelerate the diversion speed, while the lower layer will quickly absorb the diverted liquid due to water absorption to form a capillary effect. The two cooperate to make the diversion speed of the support layer faster, further reducing the occurrence of the back-seepage problem. On the other hand, a diversion layer is added between the surface layer and the sandwich structure layer of the present application, increasing the penetration effect of the liquid. On the third hand, the lower layer of the sandwich structure layer will quickly disperse and evenly distribute the absorbed liquid, thus increasing the contact area between the water-absorbing resin layer and the liquid and improving the adsorption rate of the water-absorbing resin layer. On the fourth hand, since the adsorption rate of the water-absorbing resin layer per unit time is limited, when the liquid flow rate is large, there will be a phenomenon that some liquid is not adsorbed in time and leaks. The non-woven paper layer of the present application can block and store the leaked liquid, increasing the contact time between the water-absorbing resin layer and the liquid so that all the liquid is absorbed, preventing the liquid from overflowing the sanitary napkin.

[0018] In some embodiments, the water-absorbing resin layer is made of a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 40-60 parts of water-absorbing resin, 1-10 parts of porous silica, and 15-25 parts of cellulose fiber.

[0019] In some embodiments, the preparation method of the water-absorbing resin includes the following steps:

[0020] A1. Mix vinyl acetic acid and terephthalic alcohol and add them to toluene, then add concentrated sulfuric acid and heat to 50-60 °C for constant stirring for 12-14 h. After the reaction is completed, extract and concentrate the organic phase to obtain compound A;

[0021] A2. Mix N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride, Compound A in Step A1 and tetramethylethylenediamine, add them to water, and stir at room temperature for 0.5 - 1.5 h to obtain a mixed solution.

[0022] A3. Dissolve chitosan in an acetic acid solution to obtain a chitosan solution. Add the chitosan solution to the mixed solution in Step A2, stir at room temperature for 20 - 22 h, then add an initiator and continue stirring for 12 - 16 h. After the reaction, dry at 40 - 50 °C, then soak the dried product in deionized water for 6 - 8 days, and dry again at 40 - 50 °C to obtain a water-absorbing resin.

[0023] Conventional sanitary napkins usually use conventional water-absorbing resins. As described above, the adsorption rate of the water-absorbing resin per unit time is limited. When the liquid flow rate is large, liquid leakage may occur, which may lead to liquid overflow. In addition, when conventional sanitary napkins are in use, they will emit an odor due to the action of microbial flora, which will affect the health of users.

[0024] The water-absorbing resin of this application uses N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride and Compound A as main raw materials to form a cross-linked structure, and forms a water-absorbing resin with an interpenetrating network by combining chitosan with this cross-linked structure. Using this water-absorbing resin to synergistically formulate a water-absorbing resin layer with porous silica and cellulose fibers can not only improve the adsorption rate of the water-absorbing resin layer per unit time, but also alleviate the problem of swelling deformation after the water-absorbing resin absorbs water and reduces comfort. In addition, this water-absorbing resin can also play a bactericidal role and slow down the generation of odor. The reason may be that, on the one hand, the water-absorbing resin of this application contains a large number of amino and hydroxyl groups, and the synergistic interpenetrating network structure can improve the water absorption rate of the water-absorbing resin. At the same time, it also contains a large number of quaternary ammonium salt structures that can remove microorganisms in the liquid and reduce the generation of odor; on the other hand, porous silica can increase the adsorption surface area of the water-absorbing resin to improve the adsorption rate, and silica can also anchor the liquid to increase the contact time between the water-absorbing resin and the liquid; on the other hand, cellulose fibers can form strong molecular cross-links on the surface of the water-absorbing resin to increase the structural stability of the hydrogel and alleviate the swelling phenomenon of the water-absorbing resin.

[0025] In some embodiments, the molar ratio of vinyl acetic acid to p-xylene glycol is 1:(2 - 2.3).

[0026] In some embodiments, in Step A2, the mass ratio of N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride and Compound A is 1:(0.9 - 1.1):(0.02 - 0.06).

[0027] In some embodiments, the mass of the chitosan is 20-30% of the total mass of N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride, and compound A in step A2.

[0028] On the other hand, the present invention provides a method for preparing a sanitary napkin with a function of rapid liquid conduction and anti-back leakage, comprising the following steps: cutting a surface layer with a thickness of 0.1-0.3 mm, a diversion layer with a thickness of 0.2-0.5 mm, a sandwich structure layer with a thickness of 2-5 mm, a water-absorbing resin layer with a thickness of 0.5-1.5 mm, and a non-dusting paper layer with a thickness of 0.1-0.3 mm according to the actual design size of the sanitary napkin, and then sewing them together in sequence to form a functional core, and covering the functional core with a pure cotton surface layer and a PET bottom film to make a sanitary napkin.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The sanitary napkin of the present invention includes a sanitary napkin body composed of a pure cotton surface layer and a PET bottom film, in which a functional core is embedded. The functional core is composed of a surface layer, a diversion layer, a sandwich structure layer, a water-absorbing resin layer, and a non-dusting paper layer. This sanitary napkin can quickly absorb liquid without back leakage, and at the same time has good air permeability, softness, and deodorizing ability.

[0031] (2) The sandwich structure layer of the present invention is composed of an upper cloth surface, a support layer, and a lower cloth surface made of specific materials. When the sandwich structure layer composed of the three is used, due to the hydrophobic effect and gravity, the support layer will quickly divert the liquid downward. In addition, when the upper layer, the support layer, and the lower layer are used in cooperation, a pressure difference and capillary effect will be formed, so that the diversion speed of the sandwich structure layer is faster, further reducing the occurrence of the back leakage problem.

[0032] (3) The diversion layer of the present invention can increase the distance between the surface layer and the sandwich structure layer, thereby improving the liquid penetration effect.

[0033] (4) The water-absorbing resin layer of the present invention is located between the sandwich structure layer and the non-dusting paper layer. On the one hand, the lower layer of the sandwich structure layer will quickly disperse and evenly distribute the absorbed liquid, thereby increasing the contact area between the water-absorbing resin layer and the liquid and improving the adsorption rate of the water-absorbing resin layer; on the other hand, the non-dusting paper layer can block and store the liquid in the above-mentioned missed part, increasing the contact time between the water-absorbing resin layer and the liquid, so that all the liquid is absorbed, preventing the liquid from overflowing the sanitary napkin.

[0034] (5) The water-absorbing resin layer of the present invention is composed of a water-absorbing resin, porous silica, and cellulose fibers. Among them, the porous silica can increase the adsorption surface area of the water-absorbing resin to improve the adsorption rate. At the same time, the silica can also anchor the liquid to increase the contact time between the water-absorbing resin and the liquid and prevent the liquid from overflowing. In addition, the cellulose fibers can form strong molecular cross-links on the surface of the water-absorbing resin to increase the structural stability of the hydrogel, relieve the swelling phenomenon of the water-absorbing resin, and thus maintain the comfort during the use of the sanitary napkin.

[0035] (6) The water-absorbing resin of the present invention contains a large number of amino and hydroxyl groups. The synergistic interpenetrating network structure can improve the water absorption rate of the water-absorbing resin. At the same time, it also contains a large number of quaternary ammonium salt structures, which can remove microorganisms in the liquid and reduce the generation of odors. Brief Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the internal structure of the sanitary napkin;

[0037] Figure 2 It is an enlarged view of the sandwich structure in Examples 1 to 3;

[0038] Figure 3 It is an enlarged view of the sandwich structure in Example 4.

[0039] Reference Numerals: 1 - pure cotton surface layer; 2 - surface layer; 3 - diversion layer; 4 - sandwich structure layer; 5 - water-absorbing resin layer; 6 - non-woven paper layer; 7 - PET bottom film; 8 - upper cloth surface; 8' - upper cloth surface; 9 - lower cloth surface; 9' - lower cloth surface; 10 - support layer; 10' - support layer. Detailed Embodiments

[0040] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and implementation schemes of the present invention.

[0041] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not used to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0042] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which this invention pertains. Although this invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of this invention. Various improvements and changes can be made to the specific embodiments of the description of this invention without departing from the scope or spirit of this invention, which will be obvious to those skilled in the art. Other embodiments obtained from the description of this invention will be obvious to those skilled in the art. The description and examples of this application are merely exemplary.

[0043] In each preparation example, chitosan was purchased from Shandong Guante Biotechnology Co., Ltd.; polyester fiber was purchased from Tai'an Haili New Materials Co., Ltd.; cellulose fiber was purchased from Tai'an Senyang Composite Materials Co., Ltd.; cotton fiber was purchased from Lingshou Jiasuo Building Materials Processing Co., Ltd.; polypropylene was purchased from Hebei Houkang Mineral Products Co., Ltd.; polyester was purchased from Hangzhou Xiaoshan Longfeng Chemical Fiber Co., Ltd.

[0044] Preparation Example 1

[0045] A method for preparing a water-absorbing resin, comprising the following steps:

[0046] A1. Mix 2.6 g of vinyl acetic acid and 9.1 g of terephthalyl alcohol and add them to 200 mL of toluene. Then add 1.5 g of 98 wt% sulfuric acid and heat to 55 °C and stir at a constant temperature for 13 h. After the reaction is completed, extract and concentrate the organic phase to obtain compound A;

[0047] A2. Mix 120 g of N-vinylpyrrolidone, 120 g of methacryloyloxyethyl trimethyl ammonium chloride, 7.2 g of compound A in step A1, and 3.6 g of tetramethylethylenediamine and add them to 2 L of deionized water and stir at room temperature for 1 h to obtain a mixed solution;

[0048] A3. Dissolve 61.8 g of chitosan in 3 L of 2 wt% acetic acid solution to obtain a chitosan solution. Add the chitosan solution to the mixed solution in step A2, stir at room temperature for 21 h, then add 1.3 g of ammonium persulfate and continue to stir for 14 h. After the reaction is completed, dry at 45 °C, then soak the dried product in deionized water for 7 days, and then dry at 45 °C again to obtain the water-absorbing resin.

[0049] Preparation Example 2

[0050] A method for preparing a water-absorbing resin, comprising the following steps:

[0051] A1. Mix 120 g of N-vinylpyrrolidone, 120 g of methacryloyloxyethyltrimethylammonium chloride and 3.6 g of tetramethylethylenediamine, add them to 2 L of deionized water, and stir at room temperature for 1 h to obtain a mixed solution;

[0052] A2. Dissolve 61.8 g of chitosan in 3 L of 2 wt% acetic acid solution to obtain a chitosan solution. Add the chitosan solution to the mixed solution in step A1, stir at room temperature for 21 h, then add 1.3 g of ammonium persulfate and continue to stir for 14 h. After the reaction, dry at 45 °C, then soak the dried product in deionized water for 7 days, and dry again at 45 °C to obtain a water-absorbing resin.

[0053] Preparation Example 3

[0054] A method for preparing a water-absorbing resin, the specific implementation method is the same as that of Preparation Example 1, except that the mass of methacryloyloxyethyltrimethylammonium chloride is 95 g.

[0055] Preparation Example 4

[0056] A method for preparing a water-absorbing resin, the specific implementation method is the same as that of Preparation Example 1, except that the mass of chitosan is 85 g.

[0057] Preparation Example 5

[0058] A method for preparing a water-absorbing resin, the specific implementation method is the same as that of Preparation Example 1, except that in step A1, the mass of terephthalyl alcohol is 4.1 g.

[0059] Example 1

[0060] As shown in the appendix Figure 1-2 A sanitary napkin with a function of rapid liquid conduction and anti-backflow, including a sanitary napkin body. A functional core is provided in the middle of the sanitary napkin body. The functional core includes a surface layer 2, a diversion layer 3, a sandwich structure layer 4, a water-absorbing resin layer 5 and a non-woven fabric layer 6 from top to bottom. The functional core is coated with a pure cotton surface layer 1 and a PET bottom film 7.

[0061] Among them, the sandwich structure layer 4 is composed of an upper fabric surface 8, a support layer 10 and a lower fabric surface 9; the support layer 10 is formed by vertically arranging multifilaments obtained by spinning multiple polyester fibers; the water-absorbing resin layer 5 is made of a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 50 parts of water-absorbing resin, 5 parts of porous silica and 20 parts of cellulose fiber, and the water-absorbing resin is prepared by Preparation Example 1; the material of the surface layer 2 is non-woven fabric; the material of the diversion layer 3 is cotton fiber; the material of the upper fabric surface 8 is polypropylene; the material of the lower fabric surface 9 is polyester; the material of the non-woven fabric layer 6 is wood pulp.

[0062] A method for preparing a sanitary napkin with a function of rapid liquid conduction and anti-seepage, comprising the following steps: cutting the surface layer 2 with a thickness of 0.2 mm, the diversion layer 3 with a thickness of 0.3 mm, the sandwich structure layer 4 with a thickness of 3 mm, the water-absorbing resin layer 5 with a thickness of 1 mm, and the non-woven paper layer 6 with a thickness of 0.2 mm according to the size, and then sewing them together in sequence to form a functional core body, and covering the functional core body with a pure cotton surface layer 1 and a PET bottom film 7 to make a sanitary napkin.

[0063] Example 2

[0064] As shown in the attached Figure 1-2 As shown, a sanitary napkin with a function of rapid liquid conduction and anti-seepage, comprising a sanitary napkin body, a functional core body is provided in the middle of the sanitary napkin body, the functional core body sequentially includes a surface layer 2, a diversion layer 3, a sandwich structure layer 4, a water-absorbing resin layer 5 and a non-woven paper layer 6 from top to bottom, and the functional core body is covered by a pure cotton surface layer 1 and a PET bottom film 7.

[0065] Among them, the sandwich structure layer 4 is composed of an upper cloth surface 8, a support layer 10 and a lower cloth surface 9; the support layer 10 is formed by vertically arranging multiple filaments obtained by spinning polyester fibers; the water-absorbing resin layer 5 is made of a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 40 parts of water-absorbing resin, 1 part of porous silica and 15 parts of cellulose fiber; the water-absorbing resin is prepared from Preparation Example 1; the material of the surface layer 2 is non-woven fabric; the material of the diversion layer 3 is cotton fiber; the material of the upper cloth surface 8 is polypropylene; the material of the lower cloth surface 9 is polyester; the material of the non-woven paper layer 6 is wood pulp.

[0066] A method for preparing a sanitary napkin with a function of rapid liquid conduction and anti-seepage, comprising the following steps: cutting the surface layer 2 with a thickness of 0.1 mm, the diversion layer 3 with a thickness of 0.2 mm, the sandwich structure layer 4 with a thickness of 2 mm, the water-absorbing resin layer 5 with a thickness of 1.5 mm, and the non-woven paper layer 6 with a thickness of 0.1 mm according to the size, and then sewing them together in sequence to form a functional core body, and covering the functional core body with a pure cotton surface layer 1 and a PET bottom film 7 to make a sanitary napkin.

[0067] Example 3

[0068] As shown in the attached Figure 1-2 As shown, a sanitary napkin with a function of rapid liquid conduction and anti-seepage, comprising a sanitary napkin body, a functional core body is provided in the middle of the sanitary napkin body, the functional core body sequentially includes a surface layer 2, a diversion layer 3, a sandwich structure layer 4, a water-absorbing resin layer 5 and a non-woven paper layer 6 from top to bottom, and the functional core body is covered by a pure cotton surface layer 1 and a PET bottom film 7.

[0069] Among them, the sandwich structure layer 4 is composed of an upper cloth surface 8, a support layer 10, and a lower cloth surface 9; the support layer 10 is formed by vertically arranging multifilaments obtained from multiple polyester fiber spin-drawing; the water-absorbing resin layer 5 is made of a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 60 parts of water-absorbing resin, 10 parts of porous silica, and 25 parts of cellulose fiber; the water-absorbing resin is prepared from Preparation Example 1; the material of the surface layer 2 is non-woven fabric; the material of the diversion layer 3 is cotton fiber; the material of the upper cloth surface 8 is polypropylene; the material of the lower cloth surface 9 is polyester; the material of the non-woven paper layer 6 is wood pulp.

[0070] A method for preparing a sanitary napkin with a fast liquid diversion and anti-backflow function includes the following steps: cutting the surface layer 2 with a thickness of 0.3 mm, the diversion layer 3 with a thickness of 0.5 mm, the sandwich structure layer 4 with a thickness of 5 mm, the water-absorbing resin layer 5 with a thickness of 0.5 mm, and the non-woven paper layer 6 with a thickness of 0.3 mm according to the size, and then sewing them together in sequence to form a functional core body, and covering the functional core body with a pure cotton surface layer 1 and a PET bottom film 7 to make a sanitary napkin.

[0071] Example 4

[0072] As shown in the attached Figure 1 and the attached Figure 3 As shown, a sanitary napkin with a fast liquid diversion and anti-backflow function includes a sanitary napkin body, and a functional core body is provided in the middle of the sanitary napkin body. The functional core body sequentially includes a surface layer 2, a diversion layer 3, a sandwich structure layer 4, a water-absorbing resin layer 5, and a non-woven paper layer 6 from top to bottom, and the functional core body is covered with a pure cotton surface layer 1 and a PET bottom film 7.

[0073] Among them, the sandwich structure layer 4 is composed of an upper cloth surface 8', a support layer 10', and a lower cloth surface 9'; the support layer 10' is formed by cross-arranging multifilaments obtained from multiple polyester fiber spin-drawing; the water-absorbing resin layer 5 is made of a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 50 parts of water-absorbing resin, 5 parts of porous silica, and 20 parts of cellulose fiber; the water-absorbing resin is prepared from Preparation Example 1; the material of the surface layer 2 is non-woven fabric; the material of the diversion layer 3 is cotton fiber; the material of the upper cloth surface 8' is polypropylene; the material of the lower cloth surface 9' is polyester; the material of the non-woven paper layer 6 is wood pulp.

[0074] A method for preparing a sanitary napkin with a fast liquid diversion and anti-backflow function includes the following steps: cutting the surface layer 2 with a thickness of 0.2 mm, the diversion layer 3 with a thickness of 0.3 mm, the sandwich structure layer 4 with a thickness of 3 mm, the water-absorbing resin layer 5 with a thickness of 1 mm, and the non-woven paper layer 6 with a thickness of 0.2 mm according to the size, and then sewing them together in sequence to form a functional core body, and covering the functional core body with a pure cotton surface layer 1 and a PET bottom film 7 to make a sanitary napkin.

[0075] Example 5

[0076] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the water - absorbing resin is prepared by Preparation Example 2.

[0077] Example 6

[0078] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the water - absorbing resin is prepared by Preparation Example 3.

[0079] Example 7

[0080] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the water - absorbing resin is prepared by Preparation Example 4.

[0081] Example 8

[0082] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the water - absorbing resin is prepared by Preparation Example 5.

[0083] Example 9

[0084] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that porous silica is not added to the water - absorbing resin composite material.

[0085] Example 10

[0086] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that cellulose fiber is not added to the water - absorbing resin composite material.

[0087] Example 11

[0088] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the material of the support layer 10 is cotton fiber instead of polyester fiber.

[0089] Example 12

[0090] A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis and its preparation method. The specific implementation manner is the same as that of Example 1, except that the material of the upper cloth surface 8 is polypropylene replacing polyester.

[0091] Comparative Example 1

[0092] A sanitary napkin with a function of rapid liquid conduction and anti - seepage and its preparation method. The specific implementation manner is the same as that of Example 1, except that it does not contain the liquid - guiding layer 3.

[0093] Comparative Example 2

[0094] A sanitary napkin with a function of rapid liquid conduction and anti - seepage and its preparation method. The specific implementation manner is the same as that of Example 1, except that it does not contain the sandwich - structure layer 4.

[0095] Performance test:

[0096] (1) Water absorption performance test: Test according to GB / T 8939 - 2018 "Sanitary napkins (including sanitary pads)".

[0097] (2) Bacteriostatic performance: Test according to GB 15979 - 2002 "Hygienic standards for disposable sanitary products".

[0098] (3) Softness test: Use the RRD - 2000 softness tester to test the softness of the sanitary napkin before and after water absorption.

[0099] (4) Absorption rate test: Test according to GB / T 8939 - 2018 "Sanitary napkins (including sanitary pads)" and the content of the normative reference documents disclosed therein.

[0100] Test the sanitary napkins prepared in each example according to the above - mentioned method, and the test results are shown in Table 1.

[0101] Table 1

[0102]

[0103] It can be known from the data in Table 1 that the sanitary napkins prepared in Examples 1 to 4 have the characteristics of good water absorption performance, antibacterial performance, softness and fast absorption rate; in Example 5, since compound A was not added in the preparation of the superabsorbent resin, the superabsorbent resin could not form a complete interpenetrating network, resulting in a decrease in the water absorption capacity of the superabsorbent resin layer. Due to the decrease in its swelling ability, the softness of the sanitary napkin was slightly improved; in Example 6, since the mass ratio of N-vinylpyrrolidone, methacryloyloxyethyltrimethylammonium chloride and compound A was changed, the antibacterial ability of the sanitary napkin decreased; in Example 7, since the addition amount of chitosan was changed, too much chitosan led to an increase in the swelling performance of the superabsorbent resin, thereby reducing the softness and comfort of the sanitary napkin, but its water absorption capacity increased; in Example 8, since the molar ratio of vinylacetic acid and p-xylene glycol was changed, the cross-linked structure in the superabsorbent resin decreased, resulting in a decrease in the water absorption capacity and water absorption rate of the sanitary napkin, but the softness and comfort improved; in Example 9, since porous silica was not added to the superabsorbent resin composite material, the water absorption rate of the superabsorbent resin decreased, resulting in a slight reverse osmosis phenomenon in the sanitary napkin, and the water absorption capacity decreased; in Example 10, since cellulose fiber was not added to the superabsorbent resin composite material, the swelling of the superabsorbent resin layer after water absorption was obvious, resulting in a decrease in the softness and comfort of the sanitary napkin; in Example 11, since cotton fiber was used instead of polyester fiber, the flow rate of the sandwich structure layer 4 was slow, and the absorption rate of the sanitary napkin decreased; in Example 12, since polypropylene was used to replace polyester, the diffusion of the upper cloth surface 8 to the liquid was good, and no pressure difference could be formed in the sandwich structure layer 4, resulting in a decrease in the flow rate of the sandwich structure layer 4 and a decrease in the absorption rate of the sanitary napkin; in Comparative Example 1, since the sanitary napkin structure did not contain the diversion layer 3, the softness and comfort of the sanitary napkin decreased and the absorption rate also decreased; in Comparative Example 2, since the sanitary napkin structure did not contain the sandwich structure layer 4, the absorption rate and water absorption capacity of the sanitary napkin decreased, and the softness and comfort also decreased.

[0104] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A sanitary napkin with a function of rapid liquid conduction and anti - reverse osmosis, characterized in that, It includes a sanitary napkin body, with a functional core body provided in the middle of the sanitary napkin body. The functional core body sequentially includes a surface layer (2), a diversion layer (3), a sandwich structure layer (4), a water-absorbing resin layer (5) and a non-woven fabric layer (6) from top to bottom, and the functional core body is coated with a pure cotton surface layer (1) and a PET bottom film (7).

2. The sanitary napkin with the function of rapid liquid conduction and anti-backflow according to claim 1, characterized in that, The sandwich structure layer (4) is composed of an upper fabric surface (8; 8'), a support layer (10; 10') and a lower fabric surface (9; 9').

3. The sanitary napkin with the function of rapid liquid conduction and anti-seepage according to claim 2, characterized in that, The support layer (10) is formed by arranging monofilaments or multifilaments vertically or crosswise.

4. The sanitary napkin with the functions of rapid liquid conduction and anti-counterosmosis according to claim 3, wherein, The monofilaments and the multifilaments are respectively obtained by spinning single and multiple hydrophobic fibers.

5. The sanitary napkin with a fast liquid guiding and anti - reverse seepage function according to claim 1, characterized in that, The water-absorbing resin layer (5) is prepared from a water-absorbing resin composite material; the water-absorbing resin composite material includes the following components in parts by mass: 40-60 parts of water-absorbing resin, 1-10 parts of porous silica and 15-25 parts of cellulose fiber.

6. The sanitary napkin with a fast liquid guiding and anti - reverse seepage function according to claim 5, characterized in that, The preparation method of the water-absorbing resin includes the following steps: A1. Mix vinyl acetic acid and p-xylene glycol, add them to toluene, then add concentrated sulfuric acid, heat to 50-60 °C and stir at a constant temperature for 12-14 h. After the reaction ends, extract and concentrate the organic phase to obtain compound A; A2. Mix N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride, compound A in step A1 and tetramethylethylenediamine, add them to water and stir at room temperature for 0.5-1.5 h to obtain a mixed solution; A3. Dissolve chitosan in an acetic acid solution to obtain a chitosan solution, add the chitosan solution to the mixed solution in step A2, stir at room temperature for 20-22 h, then add an initiator and continue to stir for 12-16 h. After the reaction ends, dry at 40-50 °C, then soak the dried product in deionized water for 6-8 days, and dry again at 40-50 °C to obtain the water-absorbing resin.

7. The sanitary napkin with a fast liquid guiding and anti - leakage function according to claim 6, characterized in that, The molar ratio of vinyl acetic acid to p-xylene glycol is 1:(2-2.3).

8. The sanitary napkin with a fast liquid guiding and anti - reverse seepage function according to claim 6, characterized in that, In step A2, the mass ratio of N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride and compound A is 1:(0.9-1.1):(0.02-0.06).

9. The sanitary napkin with the functions of rapid liquid conduction and anti-seepage according to claim 6, wherein The mass of the chitosan is 20-30% of the total mass of N-vinylpyrrolidone, methacryloyloxyethyl trimethyl ammonium chloride and compound A in step A2.

10. A method for preparing a sanitary napkin having a fast liquid guiding and anti-backflow function according to any one of claims 1 to 9, characterized in that, It includes the following steps: Cut the surface layer (2) with a thickness of 0.1-0.3 mm, the diversion layer (3) with a thickness of 0.2-0.5 mm, the sandwich structure layer (4) with a thickness of 2-5 mm, the water-absorbing resin layer (5) with a thickness of 0.5-1.5 mm and the non-woven fabric layer (6) with a thickness of 0.1-0.3 mm according to the actual design size of the sanitary napkin, and then sew them together in sequence to make the functional core body, and use the pure cotton surface layer (1) and the PET bottom film (7) to coat the functional core body to make the sanitary napkin.

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